I believe that the easiest and fastest way to do Metal Embossing is by using Stencils. They are great for fast and easy- to -do projects. Stencils can be used with any metal but Colored aluminum seems to be the perfect match.
Here I used:
Dreamweaver's heart stencil LL567 and
Mercart's Bronze and Red aluminum. Dots around the hearts were done with the "Star Wheel"